” In Las Vegas, reports indicate that certain devices were used to modify the firearms involved,” the NRA said in a statement referring to bump fire stocks. “The National Rifle Association is calling on the Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE) to immediately review whether these devices comply with federal law. The NRA believes that devices designed to allow semi-automatic rifles to function like fully-automatic rifles should be subject to additional regulations.”

The review, performed by the ATF’s technical division, functions to clarify laws and rules around devices and substances the agency regulates. An ATF review of bump fire stocks is likely to yield no substantive changes to the availability of the devices because there is no law nor regulation prohibiting the use of a device that helps a shooter shoot faster.

The trouble comes from definitions in the National Firearms Act of 1938 which is the primary law restricting the ownership of automatic weapons. The law requires registration of machine guns and sets the definition as:

Any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot without manual reloading, by a single function of the trigger.

And there’s the rub – shoot more than one shot without reloading by a single function of the trigger. In other words, only a gun that shoots two or more times by a single actuation of the trigger is a machine gun. Bump fire stocks don’t allow a semi-automatic weapon, one that requires a trigger pull for each round fired, to now shoot multiple rounds with each pull. Instead, the devices make it possible for the shooter to pull the trigger faster than would be possible without it by using the weapon’s recoil and the physics involved with resisting that recoil. When the rifle fires, bump stocks push the user’s finger forward, releasing the trigger almost instantly. Then, when the shooter begins to recover from the recoil, the device allows the user’s finger to depress the trigger again. With an AR-15 this can exceed 600 trigger presses per minute – much faster than anyone could without aid.

There is nothing in the National Firearms Act or Gun Control Act of 1968 that talks about a device that increases a gun’s cyclic rate (rate of fire.) So the ATF review will struggle to find a regulation or law that would prohibit the sale or transfer of bump fire devices.

Short term, the ATF could issue the ruling preventing the manufacture, sale, transfer or possession, but Slide Fire, Bump Fire Systems and other manufacturers whose business relies on their sale would likely challenge it in court immediately. Their challenge would succeed at the Supreme Court level. It will literally take an act of Congress to ban these items in a manner that would survive a Constitutional challenge.

That means that the NRA’s call for new regulations will require a new law and Senator Diane Feinstein has a bill, S. 1916 “To prohibit the possession or transfer of certain firearm accessories”, ready to go that will supposedly ban bump fire stocks from being made, sold, transferred or possessed in the United States. CDN will post the full text of the bill and an analysis of it once it is made public.